I think it is not worth spending all the time and effort to create a new forum software just for one forum. You are better of using Mybb and make your own customisation via plugins.
i'm not as interested in Foruming as I once was I still am though so many good times tbh
But once I get unlimited internet back I have huge ideas for a social gaming site build from scratch but I prefer not disclose any features in case someone decides to take them.
I only got 8GB monthly for the next few months so no point atm..
General rule of "Should I make it?" is "Do I have to?".
Really, if you don't need to make a new software and can just use plugins, there should be no issue. If you need to rewrite parts of MyBB itself, then a fork can be done with a few changes imported when necessary. However, it's pretty drastic to need your own forum software.
If you want to then yes. Every other software developer started in the same place as you. Having a passion for code and wanting to do something with it and with your ideas.